PDF to HTML

New in 1.17.0.

PdfToHtml turns any PDF, not only those PdfPecker made, into one HTML file that looks like the PDF. Each page is an image of the page, and the page's text is laid invisibly over it word by word, so it can be selected, copied, found with the browser's search and read by screen readers. The PDF's web, mail and phone links and its links between pages keep working. Use it to show statements, invoices or reports in a web page or an e-mail portal without a PDF viewer.

// Any PDF as one self-contained HTML page
string html = PdfToHtml.Convert(File.ReadAllBytes("statement.pdf"));

// File to file, or straight to a stream a few pages at a time, so a long PDF is never held in memory whole
PdfToHtml.ConvertFile("report.pdf", "report.html");
using (var file = File.Create("report.html")) PdfToHtml.Convert(pdfBytes, file);

// Some pages of an encrypted PDF, as sharper JPEG images
string first = PdfToHtml.Convert(pdfBytes, new PdfHtmlOptions
{
    Password = "pw",
    Pages = PdfPageRange.Parse("1-3"),
    Dpi = 200,
    ImageFormat = PdfImageFormat.Jpeg,
    Quality = 80,
});

Convert also takes a Stream, and every method takes a CancellationToken.

The HTML

The output is one self-contained HTML file with no scripts: the page images, the style sheet and the small web font of the text layer are all inside it, so it can be saved, mailed or served as it is. Pages scale to the width of the window, down to a phone screen, and print on paper of their own size. Every page is a div with the class pdf-page and the id page- followed by its page number, so report.html#page-3 opens the third page.

The pages are drawn by PdfPecker's own PDF renderer and the text comes from text extraction, so everything those can read works here: any fonts, JPEG 2000, JBIG2 and CCITT images, encrypted PDFs, form fields and annotations. Pages are converted in parallel.

Options

`PdfHtmlOptions`	Default
`Password`	none	The user or owner password of an encrypted PDF
`Pages`	every page	The pages to convert, such as `PdfPageRange.Parse("1-3")`
`Dpi`	150	The resolution of the page images; higher is sharper on high-density screens and makes larger files
`ImageFormat`	`WebP`	`WebP` (lossless), `Png`, or `Jpeg` (smaller for photos and scans, but lossy)
`Quality`	85	The JPEG quality, or the WebP compression effort, from 1 to 100
`IncludeText`	true	Lay the text invisibly over the images
`IncludeLinks`	true	Turn web, mail, phone and page links into links; `javascript:` and file links are always left out
`RenderAnnotations`	true	Draw form fields, stamps and comments, and include their text
`Title`	the PDF's title	The HTML document's title
`MaxDimension`	16,384	The most pixels on either side of a page image; larger pages get a lower resolution
`MaxPages`	10,000	More pages throw `PdfLimitException`
`MaxDegreeOfParallelism`	processor count	The most pages converted at the same time

What it is not

The HTML keeps the PDF's layout rather than reflowing it into paragraphs and tables, and the text is shown in the image rather than in the PDF's fonts, so it zooms as an image does. Text that the PDF draws only as outlines or images, such as a scan, can be seen but not selected, since there is no OCR. See Limitations.